Process of treating slimes in ore reduction.



PATENTBD APR. 18, 1905.

l G. A. DUNCAN. PROCESS 0F TREATING SLIMBS IN URE REDUCTION.

APPLICATION FILED JULY 2. 1904.

l i lill flhaiTiD STATES Patented April 18, 19(.5.

GUSTVUS A. DUNCAN, OF IHCAINVOOD, SOUTH DAKOTA.

PROCESS OF TREATING SLIIVlES IN ORE REDUCTION.

SPECIFICATION forming part of Letters Patent No. 787,878, dated April 18, 1905,

Original application filed March 27,1904, Serial No. 205,070. Divided and this application filed July 2,1904. Serial No. 215,173.

Be it known that l, G'Usrxviis A. DUNCAN, a citizen of the United States, residing at Deadwood, in the county of Lawrence and State of South Dakota, have invented new and useful lnipri'ivements in Processes of Treating Slinies in Cre Reduction, of which l the following is a specification, reference being had to the accompanyingdrawings, foi'ining a part thereof.

This application is a division of my application. Serial No. 205,070, filed March 2T, 190i.

This invention relates to the treatment of slimes containing metal values, its purpose being to provide a simplified and economical process for separating the metal values from such sliines.

It consists of the steps and (Viperations of the process hereinafter set out, and specified in the claims.

ln the drawings I have shown apparatus suitable for employment of the herein-described process which constitutes the piesent invention. This apparatus, however, is illustrated only for the purpose of rendering the process intelligible, and it is in many of its essential features the subject of other applications for patentvsuch as, for example, the applica-tion of (,)liver P. Ankeny, Serial No. ll)$,()Tb`, filed A\[arch .l-l, i904.

ln the drawings, Figure l is a plan view of an apparatus employed in the herein-described process constituting my invention. Fig. 2 is a vertical section through one of the tanks, section being made at the line 2 '2 on Fig. l.

ln practicing my invention l employ one or more tanks or vats A, in each of which there is suspended a filtering-cell B, which is only enough less in horizontal dimensions than t-he tank in which it is suspended to leave room for the accumulation upon its lateral surfaces of a predetermined thickness of slimes and enough additional space outside the same when so accumulated for the necessary circulation of the liquor or cleansingwater at the different stages of the process I hereinafter described. In each of the cells there are any desired number of pipes C C C, connected to a pumping apparatus, coiiveiitionally represented at l), tor sucking the l liquid in the tank and in which the cells are immersed through the filtering-walls of the cells to cause the deposit of solids upon the outer walls of the latter. These pipes for this purpose extend from the top down to a point near the bottom of the cells, where they open to take in the liquid. The liquid shown in the tank in Fig. 2 maybe understood to be sliine-beariiig liquid, the slime being supposedly charged with metal values which it is the purpose of the process to extract and the liquid being also charged with a proper metalsolvent liquor adapted to the mineral chai'- acter of the sliines. Pipes E l E, extending longitudinally under the bottom of each tank, have their outer curved surface only partly exposed and are perforated at the lower sides for the discharge of air at a multiplicity of points into the liquid in the tanks to keep the saine agit-ated and cause the slinies to remain in suspension. These pipes may be understood to be connected with any source of air, (not shown,) by which the air-discharge is maintained as described. The slime-bearing liquid is supplied continuously at the top of the tank, as indicated by the pipes F, extending along the top of the tanks, and discharging into them at frequent intervals, (indicated by the discharge-nipples F F,) the supply being made adequate to make good the drainage effected by suction through the filtering-walls of the cells and carried olll by the pipes C until the desired thickness of deposit of slime is produced upon the outer walls of the cells. Thereupon the supply of slimebearing liquid being ciit olf the suction will be continued through the pipes C until the liquid is substantially exhausted from the tank down to the bottom of the cell, the airsupply through the pipes E being reduced, if necessary, as the level of the liquid falls, so as not to produce undue agitation inthe reduced quantity. freshmetal-solventliquoradapted to attack and take up the metal values still contained inthe sliines will now be introduced into the tank, either through the pipes .1C or if by reason of the smallness of their discharge-apertures this method is too slow then through similar pipes (il, having i'reer dischaige at Vl'reqiient intervals, (indicated by TOO the apertures g, for example,) and the tank being kept filled with such solvent liquor, suction being applied as before through the pipes C, such solvent liquor will be sucked in through the slimes deposited on the cells and will dissolve out the metal values in the latter, and the discharge from the pumps being collected may be treated in the customary manner for recovery of metal values from the liquor thus drawn through the slimes. After this step in the operaion has been continued for a sufficient length of time .to extract the metal from the slimes to such degree as may be economically effected in this manner the metal-solvent liquor will be withdrawn by cutting 0H the supply and continuing the suction until the tank is empty or by directly draining the tank through the bottom, if preferred, and a supply of clear water will be furnished through the pipes E orl G. The tank being filled with water to the top of the cells and the section continued, the remainder of metal-solvent liquor with whatever metal values it may carry will be washed out of the slimes and collected for further treatment. After the slimes have been thus thoroughly washed out, so that not only all the metal values possible but all the solvent liquor worth recovering have been washed out, the slimes may be detached from the outer surface of the cells by any convenient means. A satisfactory means consists in reversing the pressure, so that water is forced into instead of drawn out of the cells and by the pressure from within operating outward through the canvas forces the accumulated load of slimes 0H from the latter, so that, being detached, it falls bodily into the tank and can be carried away through the discharge-passages upon opening the same and flushing out the tank with clear water. This process also tends to clear the interstices of the canvas, leaving it in proper condition for repetition of the filtering action, when suction is again applied as at first. It is desirable also to flush ofi1 the outer surface of the canvas and assist the actionA of the interior pressure in detaching the slimes, and this is accomplished by means of water-j ets directed against the outer surface of the cells at the top of the slime deposit, which is thus attacked in position to leave no marginal residuum adhering to the canvas. For this step of the process I provide a horizontal pipe J, extending along each side of each cell at the top with discharge-apertures or nozzles for directingV a multiplicity of jets of water inward and downward against the sides of the cells. A valve K controls this entire system of flushing-pipes. With slimes of certain character the exterior flushing alone may be adequate for detaching the residuum and washing the outer surface, and in other instances the character of the slimes may be such that the interior pressure alone will detach them cleanly but in most cases it is desirable to employ the two expedients coperatively, as described.l In the drawings there is shown means for .producing the suction and pressure only in conventional manner without regard to structural details. Any familiar means for producing these effects may be employed. In the drawings it may be understood that the pump D operates to withdraw the liquid from and through the cells, as described, and that the pipe M is connected with a source of water under pressure for operating in the opposite direction when the valve M is opened and the pump is not in operation. The water supplied through the pipe M for detaching the slimes, as above described, serves also to assist in flushing out the tank and delivering the residual mud therefrom.

Vith certain sorts of slimes the deposit formed upon the cell by exhaustion of the liquid as described from within may have a tendency to crack or may be without cracking quite porous, so that when the supply of slimes is cut oif, the exhaustion continuing and lowering the level of the liquid in the tank, the air will enter so easily through the deposit as to partially defeat the action of the suction in exhausting the tank to the bottom, and some slimes may be of such quality that they will not be retained after the liquid is withdrawn from the exterior, but will fall off in cakes. In such cases when the supply of slimes is cut off a corresponding supply of solvent liquor will be admitted at the bottom through the pipes provided for that purpose, and thus the liquid will be maintained in the tank at the full level, becoming gradually deprived of the solid matter by deposit, so that it will eventually consist only of the solvent liquor, as would be the case if the slime-bearing liquor had been first exhausted and the other liquor substituted. In like manner after drawing the solvent liquor throu h the slimes for a sufficient time to comp ete the process of dissolving out the metal values the liquid-supply will be changed to clear water while the tank is still full, and the suction being continued the liquid will gradually change from solvent to pure water, and then being continued long enough to complete the washing, the supply being wholly cut oif, the suction will be continued until the tank is exhausted, and if the deposit tends to break away and fall in this process no damage will be done, because this will be only in anticipation of the next step, which will consist in freeing it by the means described.

I claim- 1. The process of treating ore slimes which consists in accumulating the slimes upon the exterior vof a filtering-cell immersed in the slime-bearing liquid, by suction from within the cell and exhausting the liquor from about such accumulated slimes, surrounding the cell having the slimes thus accumulated thereon with Vfresh metal-solvent liquor, and drawing such liquor by suction within the cell through the slimes so accumulated on its exterior, and subsequently detaching the residual slimes from the cell.

2. The process ot treating ore slimes which consists in accumulating the slimes on the exterior ol a filtering-cell by suction Vtrom the interior ot' the cell while the latter is immersed in the slime-bearing liquid contained in a tank into which the cell intrudes: cutting ott the supply of slime-bearing liquid from about the cell and substituting a metalsolvent liquor; drawing such liquor into the cell through the slim es accumulated thereonI and conducting it away: withdrawing the solvent liquor from around the cell, and subsequently detaching the residual slimes from the cell.

I. The process of treating orc slimes which consists in accumulatingr the slimes on the exterior ot a filtering-cell by suction from within the cell while the latter is immersed in the slime-bearing liquid; cutting oll' thc supply of slime-bearing liquid `lirom around the cell; substituting a metal-solvent liquor; sucking such liquor tln'ough the slimes so accumulated into and through the cell; cutting oll' the supply ot' solvent liquor from around the cell; substituting a non-solvent liquid; sucking such liquid through the residual accumulated slimes lor washing the solvent liquor Vtrom the latter, and subsequently detaching the residual slimes trom the cell.

l. The process of treating ore slimes which consists in accumulating the slimes on the exterior ot a liltering-cell by suction 'from within the cell while the latter is immersed in the slime-bearing liquid; sucking the metal-solvent liquor through the slimes so accumulated thereon: subsequently directing water-jets against the accumulated slimes for detaching them from the cell and cleansing the latter.

5. The process of treat-ing ore slimes which consists in accumulating the slimes on the exterior of a l'ilteringcell fixcdly intruded into a tank; surrounding the cells within the tank with a slime-bearing liquid, and applying suction within the cells `for drawing the liquid through the cell-walls; cutting o'll the supply of liquid from around the cells and substituting a metal-solvent liquor; sticking such metal-solvent liquor through the accumulated slimes into and through the cell; cutting o'll' the supply ol solvent liquor from the tank; substituting non-solvent liquid; sticking such non-solvent liquid through the accumulated slimes into and through the cell; withdrawing the non-solvent liquid and detaching the residual slimes from the cell.

6. A process of treating ore slimes which consists in accumulating the slimes on the exterior of a Vfiltering-cell by suction from within the cell while the latter is immersed in the slime-bearing liquid; drawing the metal-solvent liquor by suction into the cell through the slimes so accumulated thereon and conducting away the metal-bearing liquor; cutting oll' the supply olf solvent liquor from around the cell and substituting a nonsolvent liquid; sucking such liquid through the residual accumulated slimes `for washing the solvent liquor' from the latter, and subsequently forcing water into and out through the walls ot the cell to detach the residual slimes from the exterior thereoli.

7. A process of treating ore slimes which consists in accumulating the slinies on the exterior o'l" a iltcring-cell by suction il'rom within the cell while the latter is immersed in the slime-bearing liquid; cutting ofl the supply o'l slime-bearing liquid from around the cell; substituting a metal-solvent liquor; sucking such liquor through the slimes so ac cumulated into and through the cell; cutting o'llf the supply of solvent liquor 'from around the cell; substituting a non-solvent liquid; sucking such liquid through the residual accumulated slimes for washing the solvent liquor lrom the latter; applying liquid-presw sure within the cell operating outward lor dctaching the residual slimes, and simultaneously directing water-jets against the outer surface ol: the cell at the top oll the accumulated slimes.

In testimony whereof I have hereunto set Vmy hand, in thc presence of two witnesses, at Deadwood; South Dakota; this 23d day of June, A. D. 1904.

GUSTAVUS A., DUNCAN.

In presence ol?- JASON XV. BAKER, R. C. HAYES.

IOO 

